Abrasive drum



July 22, 1958 I A. BLOCK ABRASIVE DRUM Filed March 27, 1957 2Sheets-Sheet 1 ?munuu n INVENTOR. flLECZ BLOCK Unitd rates PatentABRASIVE DRUM Aleck Block, Los Angeles, Calif, assignor to MeritProducts, Inc., Culver City, Calif., a corporation of CaliforniaApplication March 27, 1957, Serial No. 648,876

10 Claims. (Cl. 51193.7)

This invention relates to abrasive drums, and included in the objects ofthis invention are:

First, to provide an abrasive drum which is particularly designed toutilize wide sheets of abrasive, each having a margin extending radiallyand backed by a supporting brush, so that the tips of the sheets mayengage a relatively wide workpiece as the drum is rotated.

Second, to provide an abrasive drum for wide sheets of abrasive whereineach abrasive sheet is wrapped on a corresponding spindle rotatablysupported at each axial end of the drum, and wherein the severalspindles are gear connected so as to rotate in unison to advance theabrasive sheets as their extremities become worn.

Third, to provide an abrasive drum of this type wherein the abrasivesheet supporting spindles are tubular and are longitudinally slit, andan end of the drum is provided with slots adapted to register therewith,when the spindles are turned to predetermined positions, and wherein theabrasive sheets are provided with retainer strips arranged to slipaxially into the spindles; whereupon the spindles may be rotated inunison to wrap the abrasive sheets thereon, thereby providing a simpleyet eflective means for quickly assembling the abrasive sheets on thedrum or for quickly replacing worn sheets.

With the above and other objects in view, as may appear hereinafter,reference is directed to the accompanying drawings in which:

Figure 1 is a longitudinal sectional view of the abrasive drum takensubstantially through 1--1 of Fig. 2;

Fig. 2 is an end view of the abrasive drum with portions broken away;

Fig. 3 is a fragmentary view of the opposite end of the abrasive drumwith portions broken away.

The abrasive drum includes a shaft 1 on which iscentered a pair of endplates 2 and 3. Each end plate may be provided with an axially directedrib 4 concentric with the shaft 1. Supported on and extending betweenthe ribs 4 is a ring of abrasive sheet storage tubes 5. Each storagetube may be square in cross section. The storage tubes are preferablywelded, brazed, or otherwise secured to each other and to the endplates, or may be secured by other fastening means. The end plates 2 and3 cover the ends of the storage tubes 5.

Mounted within each storage tube isa tubular spindle 6 journaled at itsextremities in the end plates 2 and 3. The tubular spindles are equallyspaced from each other and from the axis of the shaft 1. One end of eachspindle is provided with a flange 7 which abuts the end plate 2. Eachtubular spindle 6 is provided with a longitudinal slit. 8 extending thelength of the storage tube and extending through the correspondingflange 7.

The outer side of each storage tube 5, preferably adjacent one radialwall, is provided with a longitudinal slit 9 extending the length of thestorage tube. The end plate 2 is provided with a series of slots 10,each of which intersects a bearing opening of the end plate journaling acorresponding spindle 6, and extends to theperiphery of the: end platealong a line extending radiall from the Patented July 22, 1958 axis ofthe corresponding tubular spindle passing through the slit 9 of thecorresponding storage tube 5. The spindles 6 may be turned so that theirslits 8 register with the slits 9 of the storage tubes 5 and the slots10 in the end plate 2 so that abrasive sheets may be inserted orremoved, as will be brought out hereinafter.

The flanged end of each tubular spindle 6 may be normally closed by acap screw 11.

The ends of the tubular spindles 6, opposite from the flanges 7,protrude through the end plate 3. Mounted on these protruding ends arespindle or planetary gears 12 disposed equidistant from the axis of theshaft 1.

Rotatably mounted on the shaft 1, adjacent the end plate 3, is a centralor sun gear 13 which engages all of the planetary gears 12. A collar 14retains the sun gear 13 on the shaft 1. The sun gear 13 may be providedwith spanner ring sockets 15 so that it may be manually turned to turnthe planetary gears 12 and their tubular spindles 6 simultaneously. Or,if desired, suitable turning means may be provided on any one or all ofthe planetary gears 12 to effect movement in unison of these gears.

Mounted between a pair of the planetary gears is a locking lever 16having a locking pin or screw 17 so that the locking lever 16 may bemoved into or out of engagement with the adjacent planetary gear 12 soas to lock all of the gears in various selected positions.

Each of the storage tubes 5 receives an abrasive sheet 18, the Width ofwhich is equal to the length of the storage tube. Each abrasive sheet 18is provided with retainer strips 19 suitably secured along one margin.The retainer strips 19 are of such dimension that they fit slidablywithin the tubular spindles 6.

The abrasive sheets 18 may be assembled on the drum structure byaligning the slits 8 of the tubular spindles 6 with the slits 9 of thestorage tubes 5 and slots 10 of the end plate 2; then slipping theretainer strips 19 axially into their respective spindles while theabrasive sheets 18 are slipped axially through the slots 1d and slits 9.The tubular spindles 6 may then be rotated simultaneously to wrap theabrasive sheets 18 about the spindles until the storage tubes 5 aresubstantially filled. A free margin of each abrasive sheet 18 ispermitted to remain extended substantially radially from the slit 9 ofthe corresponding storage tube 5.

Welded, brazed, or otherwise secured adjacent one margin of each slit 8is a split tube 20. A backing brush 21 is provided for each split tube.Each backing brush includes a base member 22 which fits axially in thecor-.

responding split tube 20. A series of bristles 23 extend radiallytherefrom and thus form a support for the free end of the correspondingabrasive sheet 18.

Operation of the abrasive drum is as follows:

The shaft 1 is mounted for rotation between suitable bearings, notshown. The direction of rotation is such that the abrasive sheets aredisposed at the leading sides of the backing brushes 21. The freeextremities of the abrasive sheets are adjusted so that they extendapproximately to the radial extremities of the backing brushes. This isaccomplished by rotatably adjusting the planetary gears 12 and drawingoutwardly on the free ends of the various abrasive sheets 18. It shouldbe noted that the centrifugal force exerted-during operation will alsoeifect optimum extension of the free ends of the abrasive sheets 18.

On rotation of the abrasive drum the tip ends of the abrasive sheets 18eventually wear. The planetary gears 12 are therefore adjusted from timeto time to extend the abrasive sheets. In doing so, the locking lever 16is released, the planetary gears 12 advanced one or more teeth, and thelocking: lever 16 returnedto its locking position,

When it is desired to remove the remnants of used abrasive sheets 18,the cap screws 11 are removed, the longitudinal slits 3 are turned to aposition of registry with the the slits 9 and slots 10, and the abrasivesheets are then slid axially from the spindles 6 and storage tubes 5.New abrasive sheets may then be installed.

The abrasive sheets 18 are formed of cloth or paper, coated withabrasive; or may be, in some cases, merely cloth which in the course ofuse is coated with abrasive material, such as rouge, by applying theabrasive material to the exposed ends of the sheets 18 as the drum isrotated.

It will be observed that the abrasive drum may be constructed so as tohave any reasonable axial length so that relatively wide surfaces may besanded or abraded by the abrasive drum. That is, the axial length of thedrum may be several feet if desired, so that wide material may behandled.

While a particular embodiment of this invention has been shown anddescribed, it is not intended to limit the same to the exact details ofthe construction set forth, and it embraces such changes, modifications,and equivalents of the parts and their formation and arrangement as comewithin the purview of the appended claims.

What is claimed is:

1. An abrasive drum, comprising: a drum structure including end platesand a plurality of storage tubes extending axially between said endplates and spaced equally from a common center; a tubular spindle ineach storage tube; each storage tube, its spindle, and at least one ofsaid end plates having axial slits adapted to register; abrasive sheets,each having a retainer element along one margin adapted .to be slippedendwise into a spindle as the adjacent margin of said sheet is slippedendwise into the corresponding storage tube; and means for rotating saidspindles to Wrap said abrasive sheets thereon.

2. An abrasive drum, comprising: a drum structure including end platesand a plurality of storage tubes extending axially between said endplates and spaced equally from a common center; a tubular spindle ineach storage tube; each storage tube, its spindle, and at least one ofsaid end plates having axial slits adapted to register; abrasive sheets,each having a retainer element along one margin adapted to he slippedendwise into a spindle as the adjacent margin of said sheet is slippedendwise into the corresponding storage tube; means for rotating saidspindles in unison initially to wrap said abrasive sheets about saidspindles and thereafter to feed said sheets from said spindles, therebyto extend the free ends of said sheets a selected distance radially ofsaid storage tubes; and brushes extending radially from said storagetubes to back the extended ends of said sheets.

3. An abrasive drum, comprising: a drum structure including end platesand a plurality of storage tubes extending axially between said endplates and spaced equally from a common center; a tubular spindle ineach storage tube; each storage tube, its spindle, and at least one ofsaid end plates having axial slits adapted to register; abrasive sheets,each having a retainer element along one margin adapted to be slippedendwise into a spindle as the adjacent margin of said sheet is slippedendwise into the corresponding storage tube; a planetary gear for eachspindle; and a sun gear on said shaft for engagement with all of saidplanetary gears, said planetary gears being rotatable in unison to causesaid spindles to wrap said abrasive sheets in unison thereabout.

4. An abrasive drum, comprising: a drum structure including end platesand a plurality of storage tubes extending axially between said endplates and spaced equally from a common center; a tubular spindle ineach storage tube; each storage tube, its spindle, and at least one ofsaid end plates having axial slits adapted to register; abrasive sheets,each having a retainer element along one margin adapted to be slippedendwise into a spindle as the adjacent margin of said sheet is slippedendwise into the corresponding storage tube; a planetary gear for each 4spindle; a sun gear common to said planetary gears to rotate saidplanetary gears and spindles in unison initially to wrap said abrasivesheets about said spindles, and thereafter to feed said sheets from saidspindles and extend the free ends of said sheets radially; and brushesextending radially from said storage tubes to back the extended ends ofsaid sheets.

5. An abrasive drum adapted to utilize abrasive sheets having retainerelements along one margin, comprising: a pair of end plates; a pluralityof storage tubes extending between said end plates and spaced equallyabout a common center; a tubular spindle in each tube journaled at itsextremities in said end plate; each storage tube and its spindle havinglongitudinal slits and at least one of said end plates having slots inregistry with the slits in the corresponding storage tubes, and the slitin each spindle being adapted to be rotated into registry therewithwhereby retainer elements may be inserted into said spindles with theadjacent portions of said abrasive sheets extending through said slits;and means rotating said spindles to wrap said abrasive sheetstherearound.

6. An abrasive drum adapted to utilize abrasive sheets having retainerelements along one margin, comprising: a pair of end plates; a pluralityof storage tubes extending between said end plates and spaced equallyabout a common center; a tubular spindle in each tube journaled at itsextremities in said end plate; each storage tube and its spindle havinglongitudinal slits and at least one of said end plates having slots inregistry with the slits in the corresponding storage tubes, and the slitin each spindle being adapted to be rotated into registry therewithwhereby retainer elements may be inserted into said spindles with theadjacent portions of said abrasive sheets extending through said slits;means for rotating said spindles in unison initially to wrap saidabrasive sheets about said spindles and thereafter to feed said sheetsfrom said spindles, thereby to extend the free ends of said sheets aselected distance radially of said storage tubes; and brushes extendingradially from said storage tubes to back the extended ends of saidsheets.

7. An abrasive drum adapted to utilize abrasive sheets having retainerelements along one margin, comprising: a pair of end plates; a pluralityof storage tubes extending between said end plates and spaced equallyabout a common center; a tubular spindle in each tube journaled at itsextremities in said end plate; each storage tube and its spindle havinglongitudinal slits and at least one of said end plates having slots inregistry with the slits in the corresponding storage tubes, and the slitin each spindle being adapted to be rotated into registry therewithwhereby retainer elements may be inserted into said spindles with theadjacent portions of said abrasive sheets extending through said slits;a planetary gear for each spindle; a sun gear common to said planetarygears to rotate said planetary gears and spindles in unison initially toWrap said abrasive sheets about said spindles, and thereafter to feedsaid sheets from said spindles and extend the free ends of said sheetsradially; and brushes extending radially from said storage tubes to backthe extended ends of said sheets.

8. An abrasive drum, comprising: a drum structure including end platesand a plurality of storage tubes extending axially between said endplates and spaced equally from a common center; a tubular spindle ineach storage tube; a plurality of abrasive sheets; means forinterlocking each abrasive sheet with its spindle including cooperatinginterlocking elements formed longitudinally in said spindle and along amargin of said abrasive sheet and interengageable on relativelongitudinal movement of said abrasive sheet; and means for rotatingsaid spindles to wrap said abrasive sheets on said spindles.

9. An abrasive drum adapted to utilize abrasive sheets having retainerelements along one margin, comprising: a shaft; a pair of end platesmounted for rotation on for rotating said spindles to wrap said abrasivesheets therearound; and means for locking said spindles against rotationto secure the free ends of said abrasive sheets in predeterminedextended relation with said spindles.

10. An abrasive drum, comprising: a shaft; a pair of end plates mountedfor rotation on said shaft and having rings of aligned journal boresspaced from said shaft; a plurality of spindles journaled by their endsin aligned pairs of said bores; a plurality of abrasive sheets;cooperative means on said abrasive sheets and spindles for attachingeach sheet by a margin to a corresponding spindle; a planetary gear foreach spindle; a sun gear mounted on said shaft engaging all of saidplanetary gears to rotate said spindles in unison to Wrap said abrasivesheets simultaneously thereon; and locking means engageable with atleast one of said gears to secure said gears against rotation thereby tosecure said abrasive sheets in predetermined extended relation with saidspindles.

References Cited in the file of this patent UNITED STATES PATENTS564,587 Black July 28, 1896 2,046,122 Hunt June 30, 1936 2,198,047 WickApr. 23, 1940 2,522,920 Baltes Sept. 19, 1950 2,624,217 Clark June 6,1953

